Liquefied gas dispensing system



Aug., 2 w49 R. BAKER ETAL LIQUEFIED GAS DISPENSING SYSTEM Filed Oct. 11,1943 'I ...uur

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Patented Aug. 2, 1949 UNITED STATES PATENT 'OFFICE Application October11, 1943, Serial No. 505,822

8 Claims. (Ci. 62-1) "Nw invention relates to an improvement in liquenedgas dispensing systems of the type wherein a liqueiied gas, Asuch as amixture of butano, iso-butane and propane, is stored underground orabove ground in a pressure tank in which it is vaporized by earth heator heat from the atmosphere and dispensed therefrom` for householdpurposes.

In such systems, it is customary for the liquened gas to be withdrawnfrom within the tank through a first-stage pressure regulator into avaporizer, from which the gas is directed through a suitable conduit tothe point of use, usually through a second-stage regulator. In passingthrough the rst-stage regulator drastic expansion takes place causingthe iirst-stage regulator to become very cold. The expanded gas absorbsheat to such an extent as to cause a condensing of moisture around saidregulator and vaporizer and a cooling thereof which frequently resultsin the 'freezing of the regulator valve, seriously interfering with theaction thereof.

This sometimes causes the valve to stick on its seat and prevents itfrom opening, and also the discharge port sometimes freezes closed. Whenthe regulator valve is thus prevented from opening, the supply of fuelto the appliance is cut-olf until the frozen valve eventually thaws out,or the condition is remedied by a service man.

'lihe object of this invention is to provide for the automaticby-passing of fuel in the event of freezing of the rst-stage regulatorto thaw out the regulator by the circulation of warm liqueed gastherearound, thereby providing automatically for the removal of theobstruction that would otherwise remain.

This object is accomplished by the provision ci a by-pass line from thefirst-stage regulator back to the tank for by-passing liquefied fuel tothe tank. The ilrst-stage regulator is constructed preferably with ajacket. therearound through which the liqueed fuel ilows to the tank,whereby the fuel flows through the jacket and warms the rst-stageregulator sufficiently to thaw it out and remove the frozen conditionoithe valve or discharge port thereof. Warm liquid dowing through thejacket and around the rst- Fig. 2 is a vertical sectional view through ajacketed pressure regulator; and

Fig. 3 is a cross section therethrough on the line 3 3 of Fig. ii.l

The invention is shown as applied to a liquefied gas dispensing systemin which a mixture of gases is maintained in the liquid state underpressure, and is stored in a tank designated generstage regulator willprevent the mst-stage regulator from freezing.

it preferred embodiment oi the invention is ally by the numeral I. Thistank is frequently buried underground, as shown in Fig. 1, below thefrost line when the mixture contains less than propane, so as to utilizethe heat of the surrounding earth in vaporizing the liquefied fuel. Whenmore than 50% of the mixture is propane, the boiling point of themixture is low enough to permit above-ground installations in most ofthe United States. y

A protecting casing 2 extends upwardly from the tank I to the suri'aceof the ground, when the tank is buried underground, and has the usualcover thereon that is removable for the purpose of gaining access to theiittings inside the casing. Also extending upwardly from the tank i,inside the casing 2 is a stand pipe 3 open to the interior of the tank,the top oiwhich stand pipe is connected with a unitary valved head il ofconventional construction. A liquid eduction pipe t extends upwardlyfrom a point near the bottom of the tank i, passing through the standpipe 3, and ls connected with the head t, to discharge liquefied gasfrom the tank and through a cut-off valve c to an outlet nipple G, allarranged in the protecting casing 2 and being of conventionalconstruction.

The outlet nipple t is connected with a rststage pressure regulatordesignated generally by the numeral i. the construction of which will bedescribed more in detail hereinafter. The discharge sicieof the pressureregulator i is connected through a cut-ofi' valve 8 with a pipe Siextending into the tank i and' formed preferably in a coil designated I0, mounted in the bottom oi' the tank l in position to be immersed inthe liquefied gas held in storage therein. The coil l0 forms an internalvaporizer for the liqueiled gas passing through the pipe 9, and beingheated from the body of liquid fuel contained in the tank in heatexchange relation with the surrounding earth, this vaporizing coil I0will thereby cause a vaporization of any liquefied fuel that moves pastthe mst-stage pressure regulator 1. The discharge side of the vaporizingcoil i0 is connected with a second-stage pressure regulator II ofconventional construction from lator sufficiently to be substantiallyvaporized.

When the liquid enters the first-stage regulator of the character usedheretofore, drastic expansion takes place, causing the first-stageregulator to be very cold. Because of refrigeration caused by expansion,the moisture present in the liquefied gas flowing past the first-stageregulator through the discharge port thereof freezes on the seat andsides of the wall of the discharge port, therebystopping the flow ofgas.

To prevent/freezing of the first-stage regulator, we have devised afirst-stage regulator which will by-pass fuel in heat exchange relationwith the valve or regulator seat, causing a thawing out of the frozencondition of the regulator, if that should take place, and tending tomaintain an operative condition of the regulator in service. One form ofsuch construction is illustrated more in detail in Figs. 2 and 3.

In this form, the regulator 1 is constructed of a casing I4 divided by atransverse wall I5 extending from one side thereof substantially to theopposite side, and separating the casing into a valve chamber I6 and aby-pass chamber I1. The valve chamber I6 has an inlet I8 connected withthe nipple 6 from the head 4.

The valve chamber I6 also has an outlet surrounded by a valve seat I9 inposition to be engaged by a valve 2li carried by a valve stem 2I,extending to and supported by a diaphragm 22,

. The diaphragm 22 is mounted between the casing I4 and its head 29 thatis secured to the casing. A spring 24 bears against one side of thediaphragm 22, while a spring 25 bears in the opposite direction againstthe valve 20, tending to seat the valve. The springs 24 and 25 are ofadjustable tension, having plugs 29 and 21, respectively, mounting thesame, and screw-threaded in the head 29 and in the partition I5, asshown in the drawings. A plug 29 in the casing I4 may be removed foraccess to the plug 21. Spring 24 is of greater strength, and normallytends to unseat the valve 20, although the pressure acting on thediaphragm tends to seat the valve.

The by-pass chamber I1 communicates with the valve chamber I6 andextends around the sides of an outlet chamber 29, as shown in Fig. 3,

. whereit communicates with a fluid jacket 90 in the head 23, whichcommunication is shown as formed by openings 3I inthe casing I4providing open communication between these parts. wise, the valvechamber I6 is in open communication at 32 with the liquid jacket 90, andat 3l with the by-pass chamber I1. Thus, the liquefied gas flowing intothe valve chamber I6 will pass also into the by-pass chamber I1 and maybe discharged from the latter through a pipe 34 extending into the tankI to a point adjacent the bottom thereof, as shown in Fig. 1.

'I'he fuel supply pipe 9 of the vaporizer is condischarge side of thevalve 20. During the normal operation of the system, the liquefied gaswill flow through the eduction pipe 5, head 4, nipple 9, valve chamber I6, seat I9 past the open valve 20,

`and through the discharge chamber 29 to the Apipe 9 and vaporizer III.In thus passing to the 75 sure reducing regulator connected with thecon- Like- I pipe 9 under reduced pressure. there will be a sumcientreduction in pressure of the gas to cause a vaporization thereof. Thisreduction in pressure of the liquid discharged by the first-stageregulator 1 causes a drastic expansion of the fuel to take place,resulting in a substantial reduction in temperature at the first-stageregulator.

In the meantime. fuel will stand normally in the pipes 5 and I4,substantially to the same height when the system is not in operation,supplying no fuel to the appliance. The opening of the valve 20 howevercauses fuel to be drawn through the eduction pipe 5 into the valvechamber IG. and this will serve also to fill the by-pass chamber I1 andthe surrounding liquid jacket. The expansion of the fuel at the valvecauses an absorption of heat from the liquid surrounding the valvechamber, and this surrounding liquid becoming very cold, begins todescend through the by-pass pipe 34 back into the tank I. This causes athermo-syphonic circulation through the bypass chamber of warmed butaneor liquefied gas about and in heat exchange relation with the valvechamber I6. This warmed liquid from within the storage tank I willthereby maintain a warmed condition at the valve seat I9, sumcient toprevent the collection of ice at the valve seat, and will maintain thiswarmed condition during the operation of the system. This preventsmoisture present in low pressure gas from freezing on and around thevalve seat I9 and tending to '.'nected with the discharge chamber 29beyond the cause sticking of the valve 20 which would interfere with theproper operation of the system.

Thus we have provided for the circulation of warm fuel from within thertank into heat exchange relation with the first-stage regulator of a gasdispensing system which will prevent freezing of the valve thereof thatwould otherwise result from the reduction in pressure at the firststageregulator or which will maintain a sufhciently warmed condition at thevalve such that freezing of the valve would not take place.

It will be understood that the tank I is adapted to be constructed withthe usual fittings required for practical operation, which have beenomitted in the diagrammatic illustration. Otherwise, the system willfunction generally in the conventional manner, in so far as concerns thevaporization of the fuel and the discharge thereof through thesecond-stage regulator when one is required, to the point of use.

We claim:

1. A method of vaporizing a liquefied gas comprising conning said gas ina container, discharging the liquefied gas from said container through aflow line, reducing the pressure of the gas at a point in said ow lineand vaporizing said gas, and circulating liquefied gas from saidcontainer into heat exchange relation with said vaporizing gas at saidpoint and back into the container to prevent freezing at said vaporizingpoint.

2. A method of vaporizing a liquefied gas comprising confining said gasin a container, discharging the liquefied gas from said containerthrough'a conduit and through a jacketed pressure regulator forvaporization, and by-passing a portion of the liquefied gas through thejacketed pressure regulator and back into the container to preventfreezing of moisture in the regulator.

3. In a liquefied gas dispensing system, the

combination of a container for confining lique- I ed gas, a conduitconnected with the container for discharge of liquefied gas therefrom, apresattacco duit for receiving and vaporizing a portion of the liqueedgas through the conduit and reducing the pressure thereof, and means forbypassing anotherportion of the liquefied gas from said conduit in heatexchange relation with the regulator to prevent freezing thereof anddirect- 'mg the same back into the container.

d. In a liquefied gas dispensing system, the combination of a containerfor confining liquened gas, a conduit connected with the container fordischarge of liquefied gas therefrom, a pressure reducing regulatorconnected with the conduit for receiving and vaporizing a portion of theliqueed gas from the container through the conduit to reduce thepressure thereof, and means for causing a thermo-syphon circulation ofanother portion of the liqueed gas from within the container into heatexchange relation with the pressure regulator and back into thecontainer to prevent the freezing of moisture in the regulator.

5.. 1n a liqueed gas dispensing system, the combination of a containerfor confining liqueed gas, a conduit connected with the container fordischarge of liquefied gas therefrom, a pressure reducing regulatorconnected with the conduit for receiving and vaporizing a portion of theliquefied gas from the container through the conduit to reduce thepressure thereof, and means for by-passing another portion of theliquefied gas from the container into heat ex-A change relation with thepressure regulator and hack into the container.

6. 1n a liqueed gas dispensing system, the combination of a containerfor confining liquened gas, a conduit connected with the container fordischarge of liquefied gas therefrom, a pressure regulator connectedwith the conduit, said pressure regulator having a liquid jacketsubstantially surrounding the major portion of said regulator, means foradmitting warmed liquid from the conduit to said jacket, and means fordirecting the liquid from the jacket back into the container.

7. The method of dispensing liquefied petroleum gas which ischaracterized by storing the gas under pressure in a storage tank,delivering means leading into and out of the contents of the storagetank to absorb heat therefrom, whereby the liquid heating mediumprevents moisture from freezing as it passes through the pressurereducing valve and thereby prevents the valve from sticking.

8. Apparatus for dispensing liquefied petroleum gas comprising, incombination, a pressure storage tank; a conduit .connected to the tankto deliver fuel therefrom; a pressure reducing valve for reducing thepressure of the fuel; a heat exchanger rcarrying a liquid heating mediumsubmerging the casing of the pressure reducing valve; and conduit meansconnected t0 the heat exchanger and extending into and out of thecontents of the storage tank to cause the liquid heating medium tocirculate through the heat exchanger.

ROBIN BAKER. JAMES C. FLEMING.

REFERENCES CITED The following references are of record in the ie ofthis patent:

UNITED STATES PATENTS Number Name Date '772,077 Theis Oct. 11, 1904880,569 Peulecke Mar. 3, 1908 1,155,602 Miles Oct. 5, 1913 1,507,073Lewis Sept. 2, 1924 1,636,919 Miller July 26, 1927 1,984,792 Ford Dec.18, 1934 1,999,269 Anderberg Apr. 30, 1935 2,011,100 Woods Aug. 13, 19352,020,492 Zahn Nov. 12, 1935 2,050,750 Drummond Aug. 11, 1936 2,176,829White Oct. 17, 1939 2,217,583 White Oct. 8, 1940 2,260,356 White Oct.28, 1941 2,286,050 Baker June 9, `1942

